1. Field of the Invention
The present invention relates to a photosensitive resin composition. More particularly, it relates to a positive type photosensitive resin composition which is suitable for application in the field of microelectronics, and is developable with an alkali aqueous solution, and a method for manufacturing a semiconductor apparatus using the composition.
2. Description of the Related Art
In application of microelectronics, a polymer exhibiting durability at high temperatures is generally widely known. The precursors of such polymers such as polyimide and polybenzoxazole (PBO) can be made photoreactive by a preferable additive. The precursors are converted into desirable polymers by a known technique such as exposure to high temperatures. Therefore, a polymer precursor is used for manufacturing a protective layer, a heat insulating layer, and a relief structure of a highly heat-resistant polymer.
U.S. Pat. No. 4,371,685 discloses a positive type photosensitive composition containing an alkali-soluble PBO precursor, and a diazoquinone photoactive compound. The diazoquinone compound prevents the PBO precursor from being dissolved in a water-based base. After exposure, the diazoquinone compound undergoes photolysis, and is converted into indene carboxylic acid which promotes the dissolution of the PBO precursor into an alkali developer.
Whereas, JP-T-2002-526795 discloses a composition containing a PBO precursor partially capped with a diazoquinone compound.
The photosensitive composition containing such a PBO precursor is a system which is less likely to provide a sufficient difference in dissolution rate between unexposed portions and exposed portions. Thus, there are problems of image performances such as sensitivity, film loss, and resolution.
In Japanese Patent No. 3346981, Japanese Patent No. 3478376, and JP-A-2005-309032, there is disclosed a composition including a polybenzoxazole precursor, a photosensitive quinone diazide compound and a phenol compound. However, the performance balance of sensitivity, the film thickness uniformity in the wafer after development, and the film thickness uniformity after curing was insufficient.